An administration of a drug solution to a patient by a syringe is carried out by a procedure such as that to be described hereinafter. After the drug solution is first drawn from an ampoule or vial and filled in a syringe barrel by using a plunger rod, the plunger rod is slowly pushed into the syringe barrel so that the drug solution is injected directly or via an infusion tube into a blood vessel or the like of the patient. Syringes, which are used as described above, are substantially the same in configuration from the request for giving priority to their basic function, and even among those having syringe barrels different in thickness and/or length because of differences in capacity, they all give a similar impression in appearance so that their own visual identifiability is extremely low. Further, syringes are fundamentally used with different kinds of drug solutions filled therein, respectively, as needed depending on the symptoms of patients. Before use, syringes of the same kind cannot hence be identified from each other at all from their appearances. In general, a syringe barrel is transparent, and a drug solution filled therein is visible from the outside. The drug solution is not characterized by color either so that, even when the drug solution has been filled in the syringe barrel, the thus-filled syringe is not provided with any substantially-improved visual identifiability. In a medical procedure, on the other hand, it is essential to absolutely avoid any misidentification or confusion with respect to each drug solution to be administered to a patient. For this purpose, it is necessary to permit clearly distinguishing a drug solution filled in a syringe barrel and its intended purpose when seen from the outside.
For permitting clearly distinguishing a drug solution filled in a syringe barrel, various measures have heretofore been taken to provide the thus-filled syringe with improved visual identifiability. Examples of such measures include to directly write necessary information, such as the name of a drug solution, the name of a patient and an intended purpose, on an outer wall of a syringe or to adhere a label bearing such information written thereon. It has also been proposed to prepare beforehand an indication member, for example, a slip of paper with necessary information such as the name of a drug solution and the name of a patient written thereon and to attach it to a syringe by a rubber band or the like. In order to resolve the difficulty in reading scale markings or the like that would arise when a label or indication member is adhered or otherwise attached to a syringe barrel, it has also been proposed to show information by inserting such an indication member in place within a bore formed in a thumb rest of the syringe (see Patent Document 1).
Patent Document 1: JP-A-2003-260136